Bowman conducts planning and design
studies for agencies considering the implementation or
improvement of activity-based forecasting models. Such a
study can help you clarify your requirements, identify good ways
of satisfying them, and understand what it will take to do
so. Bowman has conducted studies for the Southern
California Association of Governments (SCAG), the Tampa Bay
region of Florida, and the Danish Road Directorate
(Vejdirektoratet). Here are the reports from those studies
(pdf files).

Bowman conducts development projects
to implement activity-based models on the DaySim software
platform for the client's geographical region. He will
serve as prime contractor, working in partnership with your
technical model developers and any subcontractors as
needed. Or he can serve as a subcontractor to a larger
consulting firm. In either case, he usually provides the
model design services, implements customization and new features
in the DaySim software, and estimates models. In some
cases he also manages the project, processes the input data for
model development, and technically guides the other aspects of
the project. In all cases, he coordinates the DaySim
software implementation with RSG, Inc, which shares copyright of
the DaySim software with him and houses the DaySim code
repository encompassing all DaySim implementations.

Development of innovative
activity-based model features

One of Bowman's specialties is
researching new model needs that you may have as his
activity-based model client, and then designing model solutions
and incorporating them into DaySim. This is usually done
in conjunction with RSG's Mark Bradley and software
engineers. Examples of DaySim functionality that
Bowman has incorporated in this way include:
--park and ride mode with lot capacity constraints and fill
levels that vary by time of day. (Sacramento)
--partially joint half tours (e.g., when a parent drops off a
child at school on the way to work.) (Seattle and Copenhagen)
--transit and bicycle mode combinations, including
bike-park-ride-walk, bike-park-ride-bike, and bike-on-board
(Copenhagen)
Enhancements currently under consideration include:
--automated base year calibration and future year pivoting
within DaySim using base year trip matrices
--incorporation of shared mobility services (car share or bike
share)
--incorporation of autonomous vehicles

Instruction in activity-based
models

Bowman can provide instruction in
all aspects of activity-based models. This can take the
form of one or more presentations and/or discussions with an
executive, a technician, or a group. The content can be
customized to meet your needs, including such topics as needs
and benefits, data and staff requirements, how to go about a
model development project, technical workings of the AB model,
or model development methods.

Coaching for model estimation

As a model estimation coach, Bowman
guides and reviews the discrete choice model estimation of
clients who want to do their own model development but also want
to benefit from his technical knowledge and skills in
econometric discrete choice modeling. These services can
be provided as part of a major model development contract, or
under a retainer or on-call contract. Past clients include
Denver Regional Council of Governments, Puget Sound Regional
Council and Danish Road Directorate.

Model
technical evaluation and forecast evaluation

Bowman can study, understand and
critique the detailed technical workings of a travel demand
model and, optionally, estimate the uncertainty and bias in the
model's forecasts. The purpose of such evaluations might
be to identify needed model improvements or to satisfy the
requirements of investors. Bowman performed this type of
analysis for potential investors in a major Asian city's
elevated rail public transport system.

Research partnerships

Bowman serves as a prime or
subcontractor on sponsored research projects related to
activity-based models and/or non-motorized transportation.
As a subcontractor he can take a major role, or he can bring his
technical expertise to bear in an advisory capacity.

Further develops the activity
schedule model (see 1995 Thesis), emphasizing (a) the influence
of activity accessibility on activity participation, at-home vs
on-tour decisions, trip chaining and inter-tour trade-offs, and
(b) the influence of lifestyle on activity and activity pattern
utility. Includes an empirical implementation of the model
system for Portland, Oregon.

Presents an integrated activity
based discrete choice model system of an individual's daily
activity and travel schedule, intended for use in forecasting
urban passenger travel demand. The system is demonstrated
using data from the Boston metropolitan area.

Vuk, Goran,
John L. Bowman, Andrew Daly and Stephane Hess (2015) Impact of family in-home
quality time on person travel demand, Accepted for
publication in Transportation.

Introduces the concept of Primary Family
Priority Time (PFPT), which represents a high priority household
decision to spend time together for in-home activities. PFPT is
incorporated into a fully specified and operational activity
based (AB) discrete choice model system for Copenhagen, called
COMPAS, using the DaySim software platform. Structural tests and
estimation results identify two important findings. First, PFPT
has a place high in the model hierarchy, and second, strong
interactions exist between PFPT and the other day level activity
components of the model system. Forecasts are generated for a
road pricing and congestion scenario by COMPAS and a comparison
version of the model system that excludes PFPT. COMPAS with PFPT
exhibits less mode changing and time-of-day shifting in response
to pricing and congestion than the comparison version.

Presents the regional travel forecasting
model system (SACSIM) being used by the Sacramento (California)
Area Council of Governments (SACOG). The paper
explains the model system structure and components, the
integration with the traffic assignment model, calibration and
validation, sensitivity tests, model application and Federal
peer review results.

Studies the properties and performance of
an accessibility measure derived from the Day Activity Schedule
(DAS) model system, comparing it with traditional trip-based
measures, including isochrones, gravity-based measures and
simpler utility-based measures.

Proposes a comprehensive travel
demand modeling framework to identify and model the urban
development decisions of firms and developers and the mobility,
activity and travel decisions of individuals and households.

Bowman, John
L. and Mark A. Bradley (2008) Activity-Based
Models:
Approaches
used
to
achieve
integration
among
trips and tours throughout the day, presented at the
2008 European Transport Conference, Leeuwenhorst, The
Netherlands, October, 2008.

Compares various integration
techniques used by four activity-based models that have been
used for travel forecasting in the US, providing conceptual
understanding and reasoned discussion of their strengths and
weaknesses..

Bowman, John
L., Mark A. Bradley and John Gibb (2006) The Sacramento
Activity-Based Travel Demand Model:Estimation
And Validation Results, presented at the European
Transport Conference, September 18-20, 2006, Strasbourg, France.

A sequel to the
2005 ETC SACOG paper, this paper focuses on several aspects of
the model system, including the time-of-day models,
equilibration of demand and assignment, base year calibration,
and sensitivity tests.

Bradley, Mark
A. and John L. Bowman (2006) A Summary of Design Features of
Activity-Based Microsimulation Models for U.S. MPOs, white
paper presented at the TRB Conference on Innovations in Travel
Demand Modeling, May 21-23, 2006, Austin, Texas.

This short
paper provides a concise summary of important design features of
various activity-based model systems that had been implemented
orrecently designed as of May,
2006, for planning agencies in the U.S. The models described are
those for Portland, San Francisco, New York, Columbus, Atlanta,
Sacramento, Bay Area, and Denver.

Bowman, John
L. and Mark A. Bradley (2005) Disaggregate treatment of
purpose, time of day and location in an activity-based
regional travel forecasting model, European Transport
Conference, October 2005, Strasbourg, France.

Presents
model system design, data, and partial estimation results of the
activity based regional travel forecasting model system for the
Sacramento (California) Area Council of Governments (SACOG), as
it stood while under development in September, 2005.Emphasis is placed on the techniques
employed for effectively disaggregating the treatment of
purpose, time and space.

Bowman, John
L. (2004) A comparison of population synthesizers used in
microsimulation models of activity and travel demand,
working paper.

Microsimulation models that forecast
the activities and travel of urban populations create synthetic
populations and then use them to simulate the behavior of the
households and persons in that synthetic population.The features of eight population
synthesizers are compared, and suggestions are made for
incorporating the best features into future population
synthesizers.

Vovsha,
Peter, Mark A. Bradley and John L. Bowman (2004) Activity-based
travel forecasting models in the United States:Progress since 1995 and Prospects for the Future ,
presentation at the EIRASS Conference
on Progress in Activity-Based Analysis, May 28-31, 2004,
Vaeshartelt Castle, Maastricht, The Netherlands.

Describes activity-based
travel forecasting model systems implemented or under
development in Portland, San Francisco, New York, Columbus and
Atlanta, explaining attempts to incorporate behavioral realism,
discussing issues that interfere with their acceptance in
practice, and suggesting a research agenda relevant to
implementation of practical activity-based models.

Presents an identification rule and
insights for estimation of the class of error component logit
kernel models.These are logit
kernel (or mixed logit) models involving heteroscedasticity and
subsets of alternatives with shared unobserved attributes.A case study demonstrates the
specification, identification and estimation of the type of
model for which EC is useful—one with large choice set and a
choice outcome consisting of two or more variables considered
simultaneously.

Bowman, John
L., Dinesh Gopinath and Moshe Ben-Akiva (2002) Estimating
the probability distribution of a travel demand forecast,
working paper.

Presents a practical method for
estimating the probability distribution of a travel demand
forecast.Given a forecast of any
variable of interest, such as revenue or ridership, the approach
identifies independent sources of uncertainty, estimates a
probability distribution of each source, estimates the
sensitivity of the variable to each source, and then combines
the effects.A case study is
presented in which the probability distribution of a revenue
forecast is developed for a new transit system.

An examination of the theory
underlying activity based travel forecasting models, and the
classification of the differences among modeling approaches,
provide a framework that is used to compare six important
examples.

This presentation is for those who
are considering a move to activity-based models. It
describes an activity-based model, starting from the familiar
trip-based model framework. Then it explains the basic
development approaches, tasks and roles; mentions keys to
success; and offers suggestions for proceeding.

Bowman, John
L. (2008) How is an Activity-Based Model Set
Developed?presented at the Chicago
Metropolitan Agency for Planning Symposium on Developing and
Implementing an Activity-Based Travel Demand Model, August 27,
2008.

A pre-cursor of the TMIP webinar on
activity model development (see above).

Bowman, John
L. (2008) The Day Activity Schedule Approach
of Bowman, Ben-Akiva and Bradley: 1994-2008, presented
at the Transportation Research Board Innovations in Travel
Modeling Conference, June 22-24, 2008.

Traces the development of the day
activity schedule approach from its birth at MIT in 1994 through
its real-world implementations as of 2008. Includes slides
from early presentations. Emphasizes the original concepts
and findings, as well as enhancements that have occurred since
then.

Bowman, John
L. (2008) From Theory To Practice: What
can we learn from our U.S. experience? presented at
the Transportation Research Board Annual Meeting Task Force on
Moving Activity-based Approaches into Practice, January 13, 2008.

A retrospective examination of the
activity-based model development projects sponsored by regional
planning agencies in the United States. The presentation
takes a project by project look at the innovations that
occurred, then considers why some projects were more successful
than others.

DaySim is software that simulates a
day of activity and travel for each person in each household of
a synthetic population distributed throughout a given
geographical area. It does this using an integrated set of
econometric discrete choice models. DaySim uses nine
activity purposes, represents activity locations as land parcels
or microzones, and schedules activity and travel to the
minute. DaySim works iteratively with any standard or
custom software that is able to route the trips that DaySim
generates between origins and destinations and provide back to
DaySim matrices of travel times and costs.

DaySim is currently available as open source software without a
license fee through a consulting business model. That is,
if you engage one of the copyright holders (John L. Bowman, Mark
A. Bradley or Resource Systems Group) for consulting services
for its implementation, then you will be granted an open source
license to the code. The following materials provide
information about DaySim. If you are considering acquiring
DaySim and have questions, please email John_L_Bowman@alum.mit.edu.

DaySim was originally developed in
Sacramento and then used for several years until it was upgraded
to the current standard DaySim version. The following
documentation describes the original implementation and is
provided here for reference purposes only. Although the
current DaySim software is based very heavily on the original
version, these are historical documents and they differ in some
cases from the current implementation.

SACSIM is a regional
travel forecasting model system, developed in 2005 and
implemented in 2006 for the Sacramento (California) Area Council
of Governments (SACOG).The system
features an integrated econometric microsimulation of personal
activities and travel (DAYSIM) with a highly
disaggregate treatment of the purpose, time of day and location
dimensions of the modeled outcomes.Here
are various technical documents produced during the original
development and implementation of SacSim and DaySim.They provide a very detailed
description of the model system.

ALOGIT model estimation software
The discrete response models in the above papers and projects
were all estimated with ALOGIT software.ALOGIT
can be used to estimate very large MNL and nested logit models
required in practical transportation and other choice model
applications.The latest version,
ALOGIT 4, can use simulation methods to estimate logit models
with random parameters (ie, mixed logit, error-components logit,
logit kernel).For information
about ALOGIT see http://www.alogit.com.For information about potential
discounts, email John_L_Bowman@alum.mit.edu.

DaySim works
together with ALOGIT for purposes of model estimation.
When it is run in estimation mode, DaySim generates ALOGIT
control and data files instead of simulating outcomes.
ALOGIT is then used to estimate the model coefficients, and the
resulting coefficient files are read and used by DaySim when it
runs in application mode.

Resources about bicycling from Copenhagen, Denmark
Bowman lived and worked in Copenhagen, Denmark, for eleven
months during 2013 and 2014, helping his Danish colleagues
implement an activity-based model that uses the DaySim software
and handles bicycling as a transport mode more effectively than
prior Danish models. While there he experienced the world
famous Danish bicycling environment. The following
materials include English language versions of key Danish
publications that reveal how the Danes, and Copenhagen in
particular, have achieved such desirable results through
sustained thoughtful investment of money and effort. Also
included here are photo presentations by Bowman of the
Copenhagen bicycling environment, as well as his report to the
Danes on methods for incorporating bicycling more effectively
into their activity-based traffic demand model.